My back upper molar (#2) had root canal 12 years ago. Crown came off 2 years ago and was cemented back on. Came off again one month ago. There is very little/no tooth structure above gum line. Dentist recommended extraction with implant. I have researched implants and find that posterior upper molars are difficult and involve bone grafting. I am 69 years old. If the root is determined to be in good condition, isn't it advisable to try post and crown on this upper tooth?